The actor Angus Cloud died in July of an accidental overdose of cocaine, fentanyl and other substances, a northern California coroner’s office said on Thursday.

Cloud’s cause of death was “acute intoxication” due to the “combined effects of methamphetamine, cocaine, fentanyl and benzodiazepines”, the Alameda county coroner’s bureau said. The office confirmed the overdose was an accident.

The actor was declared dead at his parents’ home 31 July in Oakland. He was 25.

Cloud, who was from Oakland, rose to fame on Euphoria playing the drug dealer Fezco “Fez” O’Neill. He quickly became a fan favorite.

To some, Cloud seemed so natural as Fez that they suspected he was identical to the character – a notion the actor challenged.

“It does bother me when people are like, ‘It must be so easy! You get to go in and be yourself.’ I’m like, ‘Why don’t you go and do that?’ It’s not that simple,” Cloud told Variety. “I brought a lot to the character. You can believe what you want. It ain’t got nothing to do with me.”

Cloud had not acted before he was cast in Euphoria. He was walking down the street in New York when the casting scout Eléonore Hendricks noticed him. Cloud was resistant at first, suspecting a scam. Then the casting director Jennifer Venditti met with him, and Sam Levinson, the series creator, eventually made him a co-star in the series alongside Zendaya for its first two seasons.

In a statement at the time of his death, his family said Cloud had been struggling with the death of his father.

“Although my son was in deep grief about his father’s untimely death … his last day was a joyful one,” Lisa Cloud McLaughlin, his mother, said in a statement soon after her son’s death. “He spoke of his intent to help provide for his sisters at college and also help his mom emotionally and financially. He did not intend to end his life.

“When we hugged goodnight, we said how much we loved each other and he said he would see me in the morning.”

Conor Hickey, Cloud’s father, died on 18 May from mesothelioma, a cancer that is often caused by exposure to asbestos.

The actor had “intensely struggled with the loss” of Hickey, whose family held a funeral for him in his native Ireland in July. In one of his last social media posts, Angus Cloud shared a photo of Hickey on Instagram with the caption: “miss u breh”.

“The only comfort we have is knowing Angus is now reunited with his dad, who was his best friend. Angus was open about his battle with mental health and we hope that his passing can be a reminder to others that they are not alone and should not fight this on their own in silence,” according to the family’s statement.